The invention relates to an on-car disc brake lathe for simultaneous resurfacing of opposite sides of a brake disc for a wheel without removing the disc but only the wheel and some parts of the brake mechanism.
Such tools are often portable and are used in garages for the renovation of used brake discs without removing the discs from the automobile. After a certain working time when a brake disc is so worn down that the brake mechanism does not function optimally anymore, the brake disc must be replaced or renovated on both sides while, of course, at the same time the rest of the brake mechanism is inspected, adjusted and possibly repaired.
U.S. Pat. No. 4,226,146 and U.K. patent application No. 2,109,734 show examples of portable on-car disc brake lathes. The devices are used by removing the wheel and likewise by removing the brake-calipers, after which the brake-caliper mounting holes in the wheel suspension are used to secure the disc brake lathe unit.
Known devices of this type are often operated manually. By means of a hand wheel or the like and a gear mechanism the mechanic thus moves the resurfacing tools across the surfaces of the brake disc while the brake disc is being rotated simultaneously. However, there are motor-driven devices on the market which compared to the manual devices have the advantage that a more uniform resurfacing is achieved, among other things because of the automatic feeding of the tools.
However, devices with automatic feeding of the tools are encumbered with the drawback that they require supervision, so that the mechanic must be ready to stop the device when the situation demands such action, for example when the resurfacing tool has reached the central area of the disc or when the tools are guided in the opposite direction, i.e. outwards, as the motor in the disc brake lathe unit must be stopped in due time to avoid that the unit is damaged. Consequently, these devices require that the mechanic operates the device all the time or at least stays in the immediate vicinity to be able to stop the device in due time.